Liquid boiler



Aug. 11, 1925. 1,549,526 B. P. COULSON. JR

LIQUID BOILER Filed Nov.

1922 2 Sheets-Sheet 1 Inventor: BeVL'S R C'ouZson c71 Ag His Attormy Aug. 11, 1925.

B. P. CCULSQN, JR

LIQUID BOILER Bvz's 1-? Coulson (714-,

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Patented Aug. 11, 1925.

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NET/V YORK, ASSIGNOB TO GENERAL ELEC- TRIO COMPANY, A GORPORATIDN OF NEW YORK.

LIQUID BOILER.

Application filed. November all 101 307?! may concern.

Be it known that l, Bnvis P. COULsON, Jr., a subject of the King of Great Britain, residing at Schenectady, in the county of 6 Schenectady, State of New York, have invented certain new and useful Improvements in Liquid Boilers, of which the following is a specification.

The present invention relates to boilers for generating vapor from liquid and especially to boilers intended for vaporizing a liquid having a high boiling point as compared with water and which may be comparatively heavy. Such a liquid is mercury which is now being utilized to drive elastic fluid turbines and my invention relates particularly to a boiler for this liquid, although it is not necessarily limited thereto.

The problems involved in constructing a mercury boiler are entirely different from those met with in water boilers in that mercury is relatively expensive so that the quantity in the system must be lrept at a minimum, thus requiring small liquid spaces in the boiler. Also, mercury liquid has a very low specific heat. These two conditions necessitate a very rapid circulation of the liquid in the boiler in order to absorb the heat oi the flue gases and prevent the burning of the boiler. Also, mercury has a relatively high boiling point so that high temperatiu'es must be dealt with.

The object of my invention is to provide an in'iprovet structure and arrangement in a boiler tor vaporizing liquids such as merid for a consideration of what I be- 0 be novel and my invention, attention is rooted to the accompanying description an the claims appended thereto.

11 the drawing, Fig. 1 is a top plan View, partly in section on line 11, Fig. 2, of a boiler embodying my invention, only part or" the tubes being shown; Fig. 2 is a side elevation partly in section; Fig. 3 is a detail 4" view partly in section and partly broken away, of a group of fire tubes; Fig. l is a top plan view of a group of fire tubes showing their arrangement around a down tube;

Figs. 5, 6 and 7 are sectional views of tube groups taken on lines 55, 66 and 7-7 respectively of Fig. 3; 8 is a perspective view of a filler which is located at the bottom 01 a down tube; 'Fig. 9 is a top plan view of the filler; Fig. 10 is a vertical sectional View of a down tube; Fig. 11 is 25, 1922. Serial No. 603,374.

a top plan view thereof, and Fig. 12 is a detail sectional View.

Referring to the drawing, 15 indicates a boiler shell in which are arranged fire tubes 16 and tubes 17, which I term down tubes. The lower portion 18 of each fire tube is hexagonal with the sides of the hexagon rounded somewhat, and at its lower end it is drawn in to form a sort of surrounding groove 19. The hexagonal lower portion is of uniform cross section for the greater portion of its length and at its upper end gradually merges into a rounded portion 20 which in turn gradually decreases in diameter and merges into a hexagonal portion 21 which also decreases in diameter and finally merges into a round top portion 22. The fire tubes are arranged in groups of six around the hexagonal down tubes 17. Down tubes 1'? have rather thick walls and at their lower ends are supported on fillers n3 each of which comprises a hexagonal upwardly dished bottom plate upon which is a conical projection El provided with spaced slots 25. The upper ends of the down tubes terminate just above the rounded portions 20 of the fire tubes and are provided with six equally spaced slots 26.

The upper ends of fire tubes 16 pass through a tube sheet 27 and are welded thereto as indicated at 28. The lower end of the fire tubes are welded together and to fillers 23 as indicated at 29. The fire tubes and down tubes are pressed together in boiler shell 15 by arcuate side plates 30 the inner surfaces of wiich are shaped as indicated 31 to fit around the tubes and these side plates are torced inward to bring the tubes tightly together by wedges 32 which are driven in between side plates 30 and the boiler shell. Side plates 30 are supported on a segmental ring 33 the lower ends being held in spaced relation to ring 33 by suitable spacers 33 (Fig. 12). Ring 33 is supported by the boiler shell as by being welded at its outer edge to an angle iron 34 fastened to the boiler shell. The inner edge of ring 33' is welded to the adjacent fire tube ends in such manner that the space between the ends of side plates 30 and ring 33 communicates with the adjacent grooves 19 at the lower enus of the fire tubes. Tube sheet 27 is' welded to the upper edge of the boiler shell 7 as indicated at 35. This forms a boiler structure in which the tubes are tightly packed and held against each other. Tubes 16 form the passages for the gases which heat the boiler, the gases entering at the bottom and leaving at the top.

When the lower ends of the tubes are welded together and to tiller 23 the grooves 19 form annular liquid chambers 36 surrounding the bottoms of the tubes, which chambers are in comn'iunication with down tubes 17 through the slots 25. In addition to the sides of tee hexagonal portions 18 of the tubes being rounded somewhat, the corners are rounded oft and when the tubes are assembled, this forms at the corners of the tubes vertical star shaped liquid passages 37 which at their lower ends open into annular chambers 36 and at their upper ends merge into each other the rounded portions 20 of the tubes where they become an nular passages 88 wnich open into the larger space around the tops of the tubes above down tubes 17. Liquid passages 37 thus gradually increase in size from an intermediate point upward.

Located a short distance above down tubes 17 is a liquid bafile plate 40 through which the tubes pass and over each down tube it is provided with an opening 41 which openings serve primarily for the passage of vapor upward. Between liquid battle plate 40 and tube sheet 27 is a vapor battle plate 42. Plates 40 and 42 are supported by the tubes and also by spacing posts 43 which at their lower ends rest on down tubes 17.

Liquid is fed to the boiler through a pipe 44 located just above liquid plate 40 and vapor is withdrawn from the boiler through a pipe 45 which communicates with the space above vapor deflecting plate 42. Di rect communication between pipe 45 and the space below plate 42 is prevented by a bafile plate 46. On the side of the boiler opposite aipe 45, plate 42 is cut away as indicate at 47 to form a passage 48 which connects the space below plate 42 to the space above it.

The boiler may be supported in the furnace in any suitable manner. In the present instance it is shown as being hung on rods 49 fastened to lugs 50 fixed to the boiler shell. This arrangement permits the boiler to expand and contract freely. The brick work of the furnace is indicated at 51 and between it and the furnace is arranged a suitable seal. In the present instance the seal comprises a ring 52 the lower edge of which dips into a ring of sand 53 supported on annular platform 54. Ring 52 is an outer wall which surrounds boiler shell 15 and between which and the shell is lagging 55. In the drawing the ring and lagging are shown broken away but it will be understood that they extend to the top of the boiler.

Referring particularly to Fig. 1, it will be noted that when three tube groups each comprising a down tube and its six surrounding tubes are assembled in the boiler shell there is left among them a hexagonal space which is filled with what may be termed an odd tube as indicated at 56.

In use the liquid to be vaporized is fed to the boiler through pipe 44. Upon entering the boiler it spreads over liquid plate 40 and runs to down tubes 17 through the clearance between tubes 16 and plate 40 where the tubes pass through the plate, the edges of the holes in the plate being beveled so as to collect liquid. Some liquid may flow to down tubes 17 through openings 41, also. The liquid flows to the bottom of down tubes 17 and is fed from them through slots 25 to annular chamber 36. By providing the upwardly dished fillers 23 and the slots 25, a large surface is presented to the liquid so that a rapid transfer of heat will take place from the fillers to the liquid. This serves to quickly heat the liquid and keep down the temperature of the fillers, thus keeping the fillers at a temperature near that of the liquid. From chambers 36 the liquid circulates upwardly through passages 37 and on the way is heated and vaporized, the vapors being discharged into the space directly below liquid plate 40. The liquid level in the boiler is in a plane above the tops of down tubes 17 and below plate 40. For the vapors to pass to the other side of plate 40 they must flow through openings 41 and in flowing to openings 41 they pass over down .tubes 17. At this time if there are any liquid particles en trained in the vapors these will fall into the down tubes. Also, liquid particles left in the vapors as they approach the top of passages 37 will flow through slots 26 into the down tubes. From the space above plate 40 the vapors flow toward the left hand side of the boiler (Fig. 2) and through passage 48 to the space above plate 42. They then flow over plate 42 and across the upper end of tubes 16 to outlet conduit 45. In thus passing across and back over the fire tubes, all liquid particles are vaporized and the vapors are superheated to the desired temperature. The arrangement gives a large fire tube suri'ace for superheating the vapors and effects a heating of the vapors to a temperture but little lower than the outfiowing flue gases.

By having down tubes interspersed among the fire tubes, I am able to obtain an even distribution of the liquid throughout the boiler and a very rapid circulation of the liquid. As a result my boiler may be operated with a minimum of liquid. Also it will be noted that the boiler requires neither top nor bottom headers, is simple in structure, and can be manufactured at a low cost. All the welding for the lire tubes is on the outside where it is easily performed initially and is readily accessible for repair. The liquid in the space between ring 33 and the lower ends of side plates 30 serves to protect these parts by keeping them from overheating.

The purpose of the down tubes 17 is primarily to partially fill up the spaces made due to what in substance amounts to the omission of fire tubes sosuch a large quantity of liquid will not be required to fill them. The size or" the opening through down tubes 17 is determined by the rapidity of the circulation and the quantity of liquid required. In some cases a separate tube 17 may be omitted altogether in which case the down tube is defined by the walls of the adjacent fire tubes and will be closed at the bottom by a suitable filler 23. As many down tubes may be used as found desirable in order to obtain the desired distribution of the liquid and the efficient feeding of the liquid to the spaces between the fire tubes. Also, as is obvious, various shaped tubes may be utilized, the hexagonal tubes being only by way of example.

In accordance with the provisions of the patent statutes, I have described the principle of operation of my invention, together with the apparatus which I now consider to represent the best embodiment thereof, but I desire to have it understood that the apparatus shown is only illustrative and that the invention may be carried out by other means.

What I claim as new and desire to secure by Letters Patent of the United States, is:

1. In a boiler, a shell and a plurality of tubes mounted therein in engagement with each other, said tubes having an outline such that they are in engagement with each other over only a portion of their surfaces so as to provide a multiplicity of separate, vertical liquid spaces of small capacity between them, the tubes serving for the passage of the heating medium, some of said tubes being shorter than the others and serving as down tubes for conveying liquid to the liquid spaces at the lower ends of such spaces.

2. In a boiler, a shell and a plurality of tubes mounted therein in engagement with each other, said tubes having an outline such that they are in engagement with each other over only a portion of their surfaces so as to provide a multiplicity of separate, vertical liquid spaces of small capacity between them, the tubes serving for the passage of the heating medium, and means for supplying liquid to said vertical liquid spaces at their lower ends.

3. In a boiler, a shell and a plurality of tubes mounted therein in engagement with each other, said tubes having an outline such that they are in engagement with each other over only a portion of their surfaces so as to provide a multiplicity of separate, vertical liquid spaces of small capacity between them, the tubes serving for the passage of the heating medium, and down tubes interspersed among the first named tubes for feeding liquid to the lower ends of said liquid spaces.

l. In a boiler, a shell, fire tubes mounted therein in engagement witheach other and fastened together at their lower edges, said tubes having a contour such that there is provided between them a multiplicity of separate vertical liquid passages which increase in cross sectional area from their lower ends to their upper ends, and means for supplying liquid to the lower ends of said liquid passages.

5. In a boiler, a shell, fire tubes mounted therein in engagement with each other and fastened together at their lower edges, said tubes having a contour such that there is provided between them a multiplicity of separate vertical liquid passages which increase in cross sectional area from their lower ends to their upper ends, means forming down passages which at their lower ends communicate with the lower ends of said vertical liquid passages, and means for supplying liquid to said down passages.

6. In a boiler, a shell, fire tubes mounted therein, said tubes being in engagement with each other, except at their upper portions where they are decreased in diameter to provide a vapor space surrounding the upper ends of said tube the portions oi' said tubes in engagementbeing of such contour as to provide vertical liquid spaces among the tubes, means connecting the tubes together at their lower ends and upper ends, means forming down tubes interspersed among the fire tubes, said down tubes communicating with said liquid spaces and means for supplying liquid to said down tubes.

7. In a boiler, a shell, fire tubes mounted therein, said tubes being in engagement with each other except at their upper portions where they are decreased in diameter to provide a vapor space surrounding the upper ends of said tubes, the portions of said tubes in engagement being of such contour as to provide vertical liquid spaces among the tubes, means connecting the tubes together at their lower ends and upper ends, means forming down tubes interspersed among the fire tubes, said down tubes communicating with said liquid spaces, a'liquid plate in the upper portion of said boiler provided with openings over said down tubes, and a pipe for supplying liquid to the upper surfaces of said plate.

8. In a boiler, a shell, fire tubes therein which are in engagement with each other throughout their lower portion and are decreased in cross sectional area at their upper ends to provide a surrounding vapor space, the lower portions of said tubes being in engagement over only a part of their surfaces so as to provide vertical liquid spaces, and the lower ends of said tubes being shaped to provide annular liquid chambers with which said spaces communicate, down tubes interspersed among said fire tubes for supplying liquid to said annular liquid chambers, and means for supplying liquid to said down tubes.

9. In a boiler, a shell, fire tubes therein which are in engagement with each other throughout their lower port-ions and are decreased in cross sectional area at their upper ends to provide a surrounding vapor space, the lower portions of said tubes being in engagement over only a part of their surfaces so as to provide vertical liquid spaces, and the lower ends of said tubes being shaped to provide annular liquid chambers with which said spaces communicate, down tubes interspersed among said fire tubes for supplying liquid to said annular liquid chambers, a liquid plate through which the upper ends of said tubes project and provided with openings for the massage of liquid to the down tubes and the flow of vapor to the space above the liquid plate, and means for supplying liquid to the upper surface of said plate.

10. In a boiler, a shell, fire tubes therein which are in engagement with each other throughout their lower portions and are decreased in cross sectional area at their upper ends to provide a surrounding vapor space, the lower portions of said tubes being in engagement over only a part of their surfaces so as to provide vertical liquid spaces, and the lower ends of said tubes being shaped to provide annular liquid chambers with which said spaces communicate, down tubes interspersed among said fire tubes for supplying liquid to said annular liquid chainbers, a liquid plate through which the upper ends of said tubes project and provided with openings for the passage of liquid to the down tubes and the flow of vapor to the space above the liquid plate, means for supplying liquid to the upper surface of said plate, a vapor discharging conduit, and means for directingthe vapor over the upper ends of the fire tubes on its way to the discharge conduit.

11. A boiler comprising groups of tubes, each group comprising a polygonal shaped down tube surrounded by a plurality of polygonal shaped fire tubes, said tubes being in contact with each other over portions of their surfaces to form vertical liquid spaces and said down tube being provided with passages which communicate with said spaces.

12. A boiler comprising groups of tubes, each group comprising a down tube sur rounded by a plurality of fire tubes, said down tube and fire tubes being in engage ment with each other over portions of their surfaces and shaped to provide vertical liquid passages between them, and said down tube terminating short of the tops of the fire tubes and being provided with an axially-extending passage for conveying liquid to said liquid passages.

13. A boiler comprising tubes arranged in contact with each other, said tubes over at least a portion of their length being polygonal in shape with their outer surfaces rounded somewhat so as to define between the tubes irregular-shaped passages of small area and large surface.

14. A boiler comprising tubes arranged in contact with each other, said tubes over at least a portion of their length being polygonal in shape with their outer surfaces rounded somewhat so as to define starshaped passages between the tubes.

15. A'boiler comprising polygonal-shaped down tubes surrounded by polygonal-shaped fire tubes, all said tubes being in contact with each other and the outer surfaces of said fire tubes being rounded somewhat so as to provide star shaped, vertically extending liquid spaces, said down tubes being shorter than the fire tubes and being provided with passages for supplying liquid to said liquid spaces, and means for-supplying liquid to the upper ends of said passages.

In witness whereof, I have hereunto set my hand this 24th day of November, 1922.

BEVIS P. COULSON, JR. 

